Genes and asthma
National, Heart and Lung Institute, Imperial College
Our genes are written in long DNA molecules. We have lots of genes but, in any cell, only some of them are active at any time. The puzzle for scientists is to work out the system that switches genes on and off. Discoveries made by Peter Barnes and his team may help to find the answer.
These scientists at Imperial College want to know more about the way that genes bring on the symptoms of asthma. Lungs get inflamed when the genes that bring on an asthma attack are active - but what turns on the genes?
What the scientists have now discovered is that inactive stretches of DNA are tightly wound around by the proteins that package up the DNA and organise it in the chromosomes. Switching on a gene involves loosening the protein wrapping around the DNA and allowing the machinery of the cell to get at the genes inside.
What the team has worked out is that the cell system for loosening up the proteins around DNA is especially active in people suffering from asthma. This allows the genes that create inflammation to become active.
Steroid drugs used to treat asthma seem to work by wrapping the DNA up tightly again to stop the genes working - the problem is that this does not only affect the asthma genes.
Submitted by: Andrew Hunt, 26 August 2003
